The goal of this project is to evaluate the efficacy of a non-opiate medication, buspirone, for the alleviation of withdrawal symptoms in heroin addicts who wish to discontinue heroin use. There is preclinical evidence that buspirone attenuates withdrawal symptomatology resulting from the interruption of morphine administration. In a double-blind, placebo controlled pilot study, we observed that buspirone given as a daily dose of 30 mg was more effective than placebo in alleviating objective and subjective withdrawal symptoms in heroin addicts in the course of detoxification. This project proposes to randomize 75 heroin addicts seeking inpatient detoxification to 5 groups over a 2-year period. The trial will start with a 5-day period of stabilization on methadone. On the last 2 stabilization days, the methadone dose will be 30 mg. Group I will then be given a placebo, group II methadone in tapering doses, group III clonidine and group IV and V buspirone (30 mg and 45 mg daily). On day 14, drugs and placebo will be discontinued and patients observed for 3 days. The trial will be double blind. Withdrawal signs, psychological changes, sleep patterns and heroin craving will be monitored throughout the trial. The agents most frequently used for heroin detoxification, clonidine and methadone have advantages as well as disadvantages. Clonidine does not suppress all withdrawal symptoms and a methadone taper can be used only in licensed clinics and can be lengthy. If buspirone proved effective in alleviating heroin withdrawal symptoms as could be anticipated in light of the pilot data presented in this application, it could be used to shorten the duration of the inpatient or outpatient detoxification of heroin addicts. Buspirone has additional advantages. It is not sedating, has no withdrawal symptoms, has no abuse potential, does not potentiate central nervous system depressants and does not induce psychomotor impairment.